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Ever being bothered by the insufficient pin on your Arduino to create the number of outputs you desire?
Hello everyone, in this instructable I would like to share to you about my idea: driving 2 common cathode 7 segment display that has a total of 20 pins, 18 usable while using only 3 pins from Arduino.
Of course this is no magic, the Arduino does not drive the 7 segment leds directly, this requires additional parts which are shift register and 7 segment driver integrated circuits, namely the famous IC 74HC595N and IC CD4511 respectively.
The idea of employing a 74HC595N shift register is to increase the number of digital outputs depending the number of IC is used. It is usually more than enough. Only 3 pins required to drive a 595N IC and giving out 8 outputs in bits, meaning 8 digital I/Os, or 8 ON/OFFs.
Then, the IC CD4511 is used that it can convert 4 bit binary electrical signal into decimal that drives the 7 segment.
A fritzing file can be obtained at the end of this instructable.
Supplies:Breadboard Power Supply (Phone charger / Battery) Arduino Board 1k resistor x2 CD4511 IC x1 74HC595 IC x2 Common Cathode 7 segment display Potentiometer Wires”

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